The application of computerised modelling techniques in manufacturing system design

The absence of a definitive approach to the design of manufacturing systems signifies the importance of a control mechanism to ensure the timely application of relevant design techniques. To provide effective control, design development needs to be continually assessed in relation to the required system performance, which can only be achieved analytically through computer simulation. The technique providing the only method of accurately replicating the highly complex and dynamic interrelationships inherent within manufacturing facilities and realistically predicting system behaviour. Owing to the unique capabilities of computer simulation, its application should support and encourage a thorough investigation of all alternative designs. Allowing attention to focus specifically on critical design areas and enabling continuous assessment of system evolution. To achieve this system analysis needs to efficient, in terms of data requirements and both speed and accuracy of evaluation. To provide an effective control mechanism a hierarchical or multi-level modelling procedure has therefore been developed, specifying the appropriate degree of evaluation support necessary at each phase of design. An underlying assumption of the proposal being that evaluation is quick, easy and allows models to expand in line with design developments. However, current approaches to computer simulation are totally inappropriate to support the hierarchical evaluation. Implementation of computer simulation through traditional approaches is typically characterized by a requirement for very specialist expertise, a lengthy model development phase, and a correspondingly high expenditure. Resulting in very little and rather inappropriate use of the technique. Simulation, when used, is generally only applied to check or verify a final design proposal. Rarely is the full potential of computer simulation utilized to aid, support or complement the manufacturing system design procedure. To implement the proposed modelling procedure therefore the concept of a generic simulator was adopted, as such systems require no specialist expertise, instead facilitating quick and easy model creation, execution and modification, through simple data inputs. Previously generic simulators have tended to be too restricted, lacking the necessary flexibility to be generally applicable to manufacturing systems. Development of the ATOMS manufacturing simulator, however, has proven that such systems can be relevant to a wide range of applications, besides verifying the benefits of multi-level modelling.

Does audit improve quality in a hospital manufacturing unit?

OBJECTIVE - To establish whether auditing improves the overall quality of a hospital manufacturing unit. DESIGN - Continuous assessment of the quality level of a hospital manufacturing unit using 14 quality indicators over a nine-month period, and two periods of audit carried out towards the beginning and end of the assessment period. SETTING - The non-sterile manufacturing, sterile manufacturing and repackaging services areas at the pharmacy manufacturing unit at Queens Hospital, Burton-on- Trent. RESULTS - Compliance ratings for the second audit were better than those for the first audit, but there was no overall improvement in quality over the study period. CONCLUSION - Auditing probably improves compliance by focusing the minds of the staff involved, rather than by initiating a sustained improvement in overall quality.

Continuous retinal vessel diameter m easurements: the future in retinal vessel assessment?

PURPOSE. To establish an alternative method, sequential and diameter response analysis (SDRA), to determine dynamic retinal vessel responses and their time course in serial stimulation compared with the established method of averaged diameter responses and standard static assessment. METHODS. SDRA focuses on individual time and diameter responses, taking into account the fluctuation in baseline diameter, providing improved insight into reaction patterns when compared with established methods as delivered by retinal vessel analyzer (RVA) software. SDRA patterns were developed with measurements from 78 healthy nonsmokers and subsequently validated in a group of 21 otherwise healthy smokers. Fundus photography and retinal vessel responses were assessed by RVA, intraocular pressure by contact tonometry, and blood pressure by sphygmomanometry. RESULTS. Compared with the RVA software method, SDRA demonstrated a marked difference in retinal vessel responses to flickering light (P 0.05). As a validation of that finding, SDRA showed a strong relation between baseline retinal vessel diameter and subsequent dilatory response in both healthy subjects and smokers (P 0.001). The RVA software was unable to detect this difference or to find a difference in retinal vessel arteriovenous ratio between smokers and nonsmokers (P 0.243). However, SDRA revealed that smokers’ vessels showed both an increased level of arterial baseline diameter fluctuation before flicker stimulation (P 0.005) and an increased stiffness of retinal arterioles (P 0.035) compared with those in nonsmokers. These differences were unrelated to intraocular pressure or systemic blood pressure. CONCLUSIONS. SDRA shows promise as a tool for the assessment of vessel physiology. Further studies are needed to explore its application in patients with vascular diseases.

Achieving continuous improvement through self-assessment

In 2007 the UK Office of Government Commerce was mandated to carry out Procurement Capability Reviews (PCR) across the 16 top spending UK Government Departments. Since then, this programme has evolved into a self assessment based approach which is markedly different from the original approach. Will the move from a centre-led strategic review of procurement capability to a department-led model based on self assessment continue to strengthen and improve procurement capability across Central Civil Government? OGC is currently working with UK Government Departments to carry out their PCRs using a self-assessment tool which incorporates qualitative and quantitative measures. Results are generated based on a capability maturity model. The results are assured independently. OGC expectations are that tangible and measurable capability improvements will be realised when departments embed the self-assessment model and implement the findings as part of a continuous improvement regime. This paper is a case study, using some relevant literature to reflect on past and possible future development of the PCR self assessment scheme.

The mechanics of continuous roller bending of plates

This research initiates a study of the mechanics of four roll plate bending and provides a methodology to investigate the process experimentally. To carry out the research a suitable model bender was designed and constructed. The model bender was comprehensively instrumented with ten load cells, three torquemeters and a tachometer. A rudimentary analysis of the four roll pre-bending mode considered the three critical bending operations. The analysis also gave an assessment of the model bender capacity for the design stage. The analysis indicated that an increase in the coefficient of friction in the contact region of the pinch rolls and the plate would reduce the pinch resultant force required to end a plate to a particular bend radius. The mechanisms involved in the four roll plate bending process were investigated and a mathematical model evolved to determine the mechanics of four roll thin plate bending. A theoretical and experimental investigation was conducted for the bending of HP30 aluminium plates in both single and multipass bending modes. The study indicated that the multipass plate bending mechanics of the process varied according to the number of bending passes executed and the step decrement of the anticipated finished bend radius in any two successive passes (i.e. the bending route). Experimental results for single pass bending indicated that the rollers normally exert a higher bending load for the steady-continous bending with the pre-inactive side roll oper?tive. For the pre-bending mode and the steady-continous bending mode with the pre-active side roll operative, the former exerted the higher loads. The single pass results also indicated that the force on the side roll, the torque and power steadily increased as the anticipated bend radius decreased. Theoretical predictions for the plate internal resistance to accomplish finished bend radii of between 2500mm and 500mm for multipass bending HP30 aluminium plates, suggested that there was a certain bending route which would effectively optimise the bender capacity.

Development of a technological innovation capability assessment model:a case study of manufacturing SMEs in Sialkot, Pakistan

Small and Medium Enterprises (SMEs) play an important part in the economy of any country. Initially, a flat management hierarchy, quick response to market changes and cost competitiveness were seen as the competitive characteristics of an SME. Recently, in developed economies, technological capabilities (TCs) management- managing existing and developing or assimilating new technological capabilities for continuous process and product innovations, has become important for both large organisations and SMEs to achieve sustained competitiveness. Therefore, various technological innovation capability (TIC) models have been developed at firm level to assess firms‘ innovation capability level. These models output help policy makers and firm managers to devise policies for deepening a firm‘s technical knowledge generation, acquisition and exploitation capabilities for sustained technological competitive edge. However, in developing countries TCs management is more of TCs upgrading: acquisitions of TCs from abroad, and then assimilating, innovating and exploiting them. Most of the TIC models for developing countries delineate the level of TIC required as firms move from the acquisition to innovative level. However, these models do not provide tools for assessing the existing level of TIC of a firm and various factors affecting TIC, to help practical interventions for TCs upgrading of firms for improved or new processes and products. Recently, the Government of Pakistan (GOP) has realised the importance of TCs upgrading in SMEs-especially export-oriented, for their sustained competitiveness. The GOP has launched various initiatives with local and foreign assistance to identify ways and means of upgrading local SMEs capabilities. This research targets this gap and developed a TICs assessment model for identifying the existing level of TIC of manufacturing SMEs existing in clusters in Sialkot, Pakistan. SME executives in three different export-oriented clusters at Sialkot were interviewed to analyse technological capabilities development initiatives (CDIs) taken by them to develop and upgrade their firms‘ TCs. Data analysed at CDI, firm, cluster and cross-cluster level first helped classify interviewed firms as leader, follower and reactor, with leader firms claiming to introduce mostly new CDIs to their cluster. Second, the data analysis displayed that mostly interviewed leader firms exhibited ‗learning by interacting‘ and ‗learning by training‘ capabilities for expertise acquisition from customers and international consultants. However, these leader firms did not show much evidence of learning by using, reverse engineering and R&D capabilities, which according to the extant literature are necessary for upgrading existing TIC level and thus TCs of firm for better value-added processes and products. The research results are supported by extant literature on Sialkot clusters. Thus, in sum, a TIC assessment model was developed in this research which qualitatively identified interviewed firms‘ TIC levels, the factors affecting them, and is validated by existing literature on interviewed Sialkot clusters. Further, the research gives policy level recommendations for TIC and thus TCs upgrading at firm and cluster level for targeting better value-added markets.